From d7a9700570eb6d3e55777cda1ae1503000692bb9 Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@openwrt.org>
Date: Wed, 26 Mar 2014 10:50:09 +0000
Subject: mtd: add support for bad blocks in NAND flash

NAND flash is very likely to contain bad blocks.

Currently, mtd and therefore sysupgrade fails when it encounters a single bad block, potentially leaving an unbootable system.

This patch allows the mtd utility to skip bad blocks in NAND flash and complete sysupgrade successfully.

Patch by: Matthew Redfearn <matt.redfearn@nxp.com>
Signed-off-by: Felix Fietkau <nbd@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@40021 3c298f89-4303-0410-b956-a3cf2f4a3e73
---
 package/system/mtd/src/mtd.c | 51 +++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 46 insertions(+), 5 deletions(-)

(limited to 'package/system/mtd/src/mtd.c')

diff --git a/package/system/mtd/src/mtd.c b/package/system/mtd/src/mtd.c
index 73335f3fbe..604ca28ae2 100644
--- a/package/system/mtd/src/mtd.c
+++ b/package/system/mtd/src/mtd.c
@@ -58,6 +58,7 @@ int no_erase;
 int mtdsize = 0;
 int erasesize = 0;
 int jffs2_skip_bytes=0;
+int mtdtype = 0;
 
 int mtd_open(const char *mtd, bool block)
 {
@@ -103,10 +104,28 @@ int mtd_check_open(const char *mtd)
 	}
 	mtdsize = mtdInfo.size;
 	erasesize = mtdInfo.erasesize;
+	mtdtype = mtdInfo.type;
 
 	return fd;
 }
 
+int mtd_block_is_bad(int fd, int offset)
+{
+	int r = 0;
+	loff_t o = offset;
+
+	if (mtdtype == MTD_NANDFLASH)
+	{
+		r = ioctl(fd, MEMGETBADBLOCK, &o);
+		if (r < 0)
+		{
+			fprintf(stderr, "Failed to get erase block status\n");
+			exit(1);
+		}
+	}
+	return r;
+}
+
 int mtd_erase_block(int fd, int offset)
 {
 	struct erase_info_user mtdEraseInfo;
@@ -236,10 +255,14 @@ mtd_erase(const char *mtd)
 	for (mtdEraseInfo.start = 0;
 		 mtdEraseInfo.start < mtdsize;
 		 mtdEraseInfo.start += erasesize) {
-
-		ioctl(fd, MEMUNLOCK, &mtdEraseInfo);
-		if(ioctl(fd, MEMERASE, &mtdEraseInfo))
-			fprintf(stderr, "Failed to erase block on %s at 0x%x\n", mtd, mtdEraseInfo.start);
+		if (mtd_block_is_bad(fd, mtdEraseInfo.start)) {
+			if (!quiet)
+				fprintf(stderr, "\nSkipping bad block at 0x%x   ", mtdEraseInfo.start);
+		} else {
+			ioctl(fd, MEMUNLOCK, &mtdEraseInfo);
+			if(ioctl(fd, MEMERASE, &mtdEraseInfo))
+				fprintf(stderr, "Failed to erase block on %s at 0x%x\n", mtd, mtdEraseInfo.start);
+		}
 	}
 
 	close(fd);
@@ -324,6 +347,7 @@ mtd_write(int imagefd, const char *mtd, char *fis_layout, size_t part_offset)
 	ssize_t skip = 0;
 	uint32_t offset = 0;
 	int jffs2_replaced = 0;
+	int skip_bad_blocks = 0;
 
 #ifdef FIS_SUPPORT
 	static struct fis_part new_parts[MAX_ARGS];
@@ -429,6 +453,12 @@ resume:
 		if (buflen == 0)
 			break;
 
+		if (buflen < erasesize) {
+			/* Pad block to eraseblock size */
+			memset(&buf[buflen], 0xff, erasesize - buflen);
+			buflen = erasesize;
+		}
+
 		if (skip > 0) {
 			skip -= buflen;
 			buflen = 0;
@@ -466,10 +496,21 @@ resume:
 		/* need to erase the next block before writing data to it */
 		if(!no_erase)
 		{
-			while (w + buflen > e) {
+			while (w + buflen > e - skip_bad_blocks) {
 				if (!quiet)
 					fprintf(stderr, "\b\b\b[e]");
 
+				if (mtd_block_is_bad(fd, e)) {
+					if (!quiet)
+						fprintf(stderr, "\nSkipping bad block at 0x%08x   ", e);
+
+					skip_bad_blocks += erasesize;
+					e += erasesize;
+
+					// Move the file pointer along over the bad block.
+					lseek(fd, erasesize, SEEK_CUR);
+					continue;
+				}
 
 				if (mtd_erase_block(fd, e) < 0) {
 					if (next) {
-- 
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